This invention relates generally to a cleaning apparatus, and more particularly, concerns an apparatus for disabling cleaning without retraction.
In the image on image, multi-pass color development process, four layers of color toner (black, cyan, yellow and magenta) are developed onto the photoreceptor before transfer to paper. A separate cycle of the photoreceptor is required to accomplish the development of each color toner layer. To avoid disturbance of these images as the color toner layers are being developed, the cleaning elements must be disengaged from the photoreceptor surface until after the four toner layers have been developed and transferred to paper. After the toner image has been transferred to the paper the cleaning elements must be re-engaged to the photoreceptor to clean any residual toner which failed to transfer.
Several copiers presently use the multi-pass process before a single transfer step. The Konica 9028 machine uses a blade cleaner which is retracted from the photoreceptor drum while the color images are being developed. The Panasonic FP-C1 machine uses a single electrostatic brush cleaner which is retracted by a cam from the drum photoreceptor. The Sharp CX7500 machine uses an intermediate belt and a dual blade cleaner which is retracted from the photoreceptor belt by a solenoid during color image development. The primary, high load, blade is also retracted when the photoreceptor seam passes under the blade to avoid a motion quality disturbance. All of these methods involve movement of the cleaning device into and out of contact with the photoreceptor.
The following disclosures may be relevant to various aspects of the present invention and may be briefly summarized as follows:
U.S. Pat. No. 5,257,079 to Lange et al. discloses a cleaning brush electrically biased with an alternating current and removes discharged particles from an imaging surface. The particles on the imaging surface are discharged by a corona generating device. A second cleaning device including an insulative brush, a conductive brush or a blade, located upstream of the the first mentioned brush, in the direction of movement of the imaging surface, further removes redeposited particles therefrom.
U.S. Pat. No. 4,878,093 to Edmunds discloses a cleaning housing and supports in cleaning relationship a closely spaced combination of an upstream brush roll cleaner and an adjacent downstream foam or porometric roll cleaner. Subsequent to release of toner from the surface, toner is carried away from the charge retentive surface on the fibers of the brush or the surface of the foam rolls. A blower creates a directed air flow for the removal of toner from the cleaning rolls. Mechanical toner removal devices may also be used to release toner from the roll surfaces. The brush roll cleaner provides a primary cleaning function, while the foam roll cleaner provides a secondary cleaning function as a back up to the brush roll cleaner and an abrading function for the removal of film buildup on the charge retentive surface.